Telephone apparatus.



PATENTED APR. 16, 1907.

3 SHEETS-SHEET 1.

klwemtoz fitter/"M 3 K. KOHN. TELEPHONE APPARATUS.

APPLIOATION FILED FBB.11, 1904.

v No. 850,434.

No. 850,434. PATENTED APR. 16, 1907.

. K. KOHN. E

TELEPHONE APPARATUS.

APPLICATION FILED FBB.11, 1904.

3 SHEETSSHEET 2. 1

N .850,434. 4 PATENT'ED APR,16, 1907.

0 K. KOHN.

TELEPHONE APPARATUS. APPLIUATIOH FILED FEB. 11, 1904.

. 3 SHEETS-SHEET 3.

KOBY KOHN, OF NEW YORK, N. Y, ASSIGNOR OF ONE-HALF TO LOUIS KSENSKY, OFDENVER, COLORADO.

No. stones.

Specification of Letters Patent.

Patented April 16, 1901;.

Application filed February 11, 1904. Serial 1 To all whom it mayconcern:

Be it known that I, KOBY KOHN, a citizen of the United States,-residingin the city, county, and State of New York, have invented certain newand useful Improvements in Telephone Apparatus, of which the followingis a specification;

This invention relates to telephone systerns; and the object of theinvention. is to provide simple andefl icient means whereby when onesubscriber on a party-line either calls central or receives-a call fromcentral all other subscribers on the party-line will be prevented fromcutting in, thereby preventmg any other suliiscriher on the line fromoverhearing the conversation or any part of it, and thus insuringabsolute privacy on the line while in use.

One or the essential features of my invention is that all receivers onthe party-line are in open circuits until a subscriber calls or iscalled, when his receiver-circuit will be,

closed and all other receiver-circuits on the line be preventedlrombeing closed by the respective subscribers until the calling orcalled subscriber has. finished the conversation and all parts on theparty-line have been restored to normal position by an operator atcentral.

The invention, which may be used either with the local-generator systemor the central-enery system for calling, will be fully describedhereinafter, reference being had to the accompanying drawings, in which-I Figure 1 is a diagrammaticview illustrating my invention as used in asystem employing local generators forcalling central.

Fig. 2 is a diagrammatic view of a portion oi the apparatus employed ateach of the substations, showing the parts in a different position. Fig.3 is a plan view of one of the arniatures employed. Fig. 4 is a sideelevation. of'the resetting devices. Fig. 5 is a similar View of aportion of Fig. 4., showing the parts in a dillerent position. Fig. '6is a diagraminatic view of devices for sending currents over themain-line wires by an operator at central. Fig. 7 is a diagrammatic viewillustrating my invention as used. in connection with the central-energysystem.

it is to be understood that the invention may be embbdied in anapparatus which may form an attachment to telephones at present in useor itniay be a part of the telephone.

In Fig. 1 I have illustrated diagrammatically the devices employed at acentral station and also those at two substations a; and Z). It is to beunderstood, however, that the invention may be used with foursubstations on the party-line, of which two will be connected to theline-wires X and X X, the same as substations a, and two the same as substation I).

A is a generator of any known style for sending out an alternatingcurrent, one of such generators being at each substation, and when notin use its armature is out out at N,

which may be considered its normal condivided at each station, and it isimmaterial what its polarity nay be so far as concerns its energizationby'the generatoiiA, because the current from the latter alternating andwill thus operate a magnet of either polarity. At substation a, themagnet (I may be of the same polarity as that at substation b; but ilfour substations are on the party-line the magnets (-1 at the other twostations will he of opposite polarity to those at stations (1 and 1).Referring 110w to Fig. 1, and assuming a subscriber desires to callcentral, the gm .5 tor A is operated, and the circuit is close A therebyestablishing a circuit as l'ollows: from generator A to wire l wire lcontact F brush 0, wire C magnet 1, wire t3, brush (1, contact F wire ibrush is, coi1- tact F, wire F to the generator. This will energizethe'inagnet U and attract its armature C", pivoted at 3, with the resultthat the generatoncircuit will be broken. through the magnet C at F F.This is done to prevent the return of C", as the current beingalternating andgniagnct polarized such action would result were it notfor this break in the circuit. The receiveucircuit will be closed at G"G and G and the brush P" will be r 7 J I p engaged with contact r".(iii-rent :lroin the enerator A will then lass towlrc l wire F". n v Iline-wire J\ to wire il at the central station 7 brush ll", contact ill,brush ii wire ll", contacts ll. and-ll, wire 11?", through iiiagziet ilwire ll, to luie\viii'e X R, to wire i brush F contact l wire l in'cuci-ai'or r.

This current will energize magnet ii and art-- tract its armature ll,which is pivoted at 11 will he released to iiolily ceuioc net H will bebroken at H, H, and H and' at the same time contact H will be engagedwith brushes H and H and contact H with brushes H H and H At eachsubstation .there is a magnet E, the armature E" of which is pivoted at5 and the movement of the armature E is resisted by a comparatively weakspring E and also by a stronger spring There is an arm B pivoted at oneend, ad j acent to the armature E and its free end is provided with aiinger 1), adapted to engage a linger e on the free end of the armatureE, and these fingers are normally held in contact with each other by aspring B, which normally tends to move the free end of the finger b andwhich movement is resisted by the finger a when the armature E is in itsnormal position, as shown in Fig. 1. A stop 20 limits the movement ofthe armature E? under the influence of its spring E and a stop 21 willlimit the movement of the arm B under the influence of its spring whenthe fingers e and b have been disengaged. The arm' B carries thecontacts F and F already referred to, and also contacts E and Referringnow to the central station, when the magnet H h been operated by thegenerator('.urrent, already described, current from a battery H will besent over the linewires X X and X and through the magnets E at therespective substations, as follows: from battery 11 to wire H brush Hcontact H brush l1, wire H, wire H to wire X X, or from contact H tobrush H wire H to wire X. From the wires X X and X, respectively,current will pass to wire E, magnet E, wire E contact E, brush E, wireto the groundfthence to wire I1, brush H contact H brush H wire H backto battery H over wire H will pass through magnet H wire H,spring-contact H, contact 11 wire H' to battery, and thereby insure theattraction of the armature H after the current from th generator A hasbeen cut out at H H and ll. until the circuit through the magnet IP isbroken at H IF, as will be referred I to hereinafter. The currentpassing from the battery ll?" over the wires X X and X will thusenergize the magnet E at each of the.

substations on the line. This current, however, is of sullirientstrength only to overcome the resistance of the x pring E" to themovement of the armature It", and the latter will move unlilit engagesthe spring El, which will stop its further movement. This movement,however, is sullirient to disen- "v the finger e from the finger b, andthe 1 ii will i hen more under theiniluenee ol its ng l3 until it isarrested bythe stop 21, as

min in Fig. 2 ol the drawings. "lhismove-.

' men? of the arm will disengage contact E Part of the current passingfrom brush E, and the circuit through magnet E from the battery H willbe broken at this point; but another circuit will-be established throughE, including magnets 'C and the bell D in series, as will be hereinafterdescribed. The additional resistance of C and D-say about one thousandohms eachwillfbe too much to enable the weak current to energize Esufficiently to hold its armature against the action of spring E",andjthe armature Ewill return to normal position, as shown in Fig. 2..As the movement of arm B is the same at all substations, it will beseen that the generatorcircuit at each substation for its magnet C willbe broken at C and F and atC and F and therefore no other subscriber onthe line can close his receiver-circuit at G, G, and G until afterthe/parts are againr'estored to normal position, as will be explainedhereinafter. A metallic circuit at the calling s'ub station has,however, been establishedas follows: From l ne X X to wire G to Wire Gthrough receiver G to contact G, and, assuming the receiver has beenremoved froinits hook. hrough the hook to wire G, brush G cent: o G,brush G wire G wire G, wire F to wire X, and the calling subscriber canthus talk with central and all the other subscribers, being unable toclose their receivercircuits, cannot hear any. conversation that may becarried on. As shown, the receiver circuits are each provided with theusual secondary of an induction-coil I in close proximity to the usualprimary of an inductioncoil J. When central answers the callingsubscriber, a jack or plug is inserted at H, which will break thecircuit from battery H at H and H", thereby denergiging the magnet Hwhich will release its armature, and the-latter will be restored tonormal position by the spring H. The drop H may also be too restored toits normal position, and then the operator at central may withdraw thejack from H and permit the spring-contact Hto engage H and then thecircuit from the generator'A at the calling substation will be againcompleted toenable the person at such substation to ring off, afterwhich the operatorat n central will restore the parts at the several 5substations to normal position, as will be explained hereinafter.Assuming now-that the parts-are in normal'position and central desiresto call up a substationsay a-the opera tor at central will, first senda. comparatively I weak current over the lines X X and X to en ergizethe magnet E at each substation to re-v lease thearms B and bring themto the position shown in Fig. 2. 1

As before stated, the magnets Cat the substations are polarized, and wewill assume. that the magnets at substations wand b will respend to acurrent and those at e a 11d d to. a also a bell D of the same Vpolarityas the mag; net at its substation. hen, therefore, the

current, At each substation, there is this result.

operator at central desires to callsubstation a, he will send out acurrent over the line X to wire E, magnet E, wire E", contact E brush C,wire C through magnet O to wire,

C, brush C, contact C, brush Cl, wire C through hell i) to wire 0, wireE to the ground and back to central. This will ring bell l) atsubstation ct, energize magnet C at the same substation, and attract itsarmature C, and thereby close its receiver-circuit at G G", and G", andwhen the person at this substation lifts the receiver from the hook thereceiver-circuit will be completed, as before described. The magnet E atsubstation a is also connected to the wire X; but the magnet G and belll) at this substation will not respond to a current, They would,however, respond to a current sent over the wire X, and the magnet C andbell D at substation I) will respond to a current sent over wire X X,while those at substation (1 will respond. to a current sent over wire XX. As the arms B at the respective substations have been operated, noother substation on the line can call central or hear the conversationexcept in the case where the call is from one substation to another onthe same line.

It is desirable to provide s01i1e n1eans for informing a person desiringto can central when the line is busy that such'is the 'fact, and 1preferably employ an audible Signal for this purpose,- which is operatedby'a current from the generator A. As before statled, when a call issent from central or to central all the amps B are moved from theposition in dicated in Fig. 1 to the position indicated in Fig. 2, andthen the contact F on said arm has been disengaged from brush C andbecome engaged with brush K, and a circuit is then established fromgenerator A to wire F contact F, brush F wire F", contact F, brush K,wire K, bell K, wire K to wire F back to the generator A. It then.subscriber operates his generating he will ring the bell K at hissubstation, and so be notified that the line is busy.

As before stated, the magnet (.7 at each substation is polarized andwill attract its armature only when a positive or negatiye cur rent, asthe case may be, is sent throiigh it. If after a magnet Chas beenenergized to attract its armature and close its receiver-cm cuit theoperator at central should aecidentally or otherwise send a current ofopposite polarity over the line, the armature of the magnet C would berepulsed and its receivercircuit broken, and it is therefore desirableto provide means to prevent this action.

h'lai'iy devices might be en'iployed for this purpose, and. in Figs. 3and 4 l. have illustrated a preferred means for accomplishii'ig ing onepole of the magnet C. l proyide an In Fig. 4- the parts are shown innormal position with the armature (1" cngagarm 30 of non-magneticmaterial and. to which I attach the various contacts, such-as F and G,in any'convenient manner and at trate in these figures. This arm isprovided with an opening 31 of sufficient size to receive the armature Cloosely, as clearly shown in Fig. 3. The armature is provided withtrunnions 32, rigidly connected to it, and these pass loosely throughholes 33 in opposite walls of the opening 31 and will form the pivotalsupport oi" the armature and also of the arm 30. Near one end of theopening 31 I secure a bridge 3% to the arm, wh ch extends across theopening in position to be engaged by one end of the armature. When theparts are in normal position, as in Fig. 4;, if current of the properpolarity be sent through the magnet the armature will be attracted tothe other pole of the magnet and by its engagement with the bridge 34will carry the arm 30 with it. If the operator at central should nowsend a current of opposite polan ity over the line, the armaturec willbe restored to normal position, but it will move away from the brldge34, and consequently will not move the arm 30, as there is notsuflicient friction between the trunnions and the openings 33 to. movethe arm. The arm 30,

therefore, after once being moved by the ar- 9 mature (3 will not beagain affected by it un' til after it has been restored to its normalposition, as will be hereinafter explained.

I will now describe the means preferably employed for resetting the armB and the armature C" and the arm 30. The magnet E is utilized for thispurpose, and all the resetting is ellected by the movement of thearmature E". the armature E its full stroke toward. the magnet E andovercome the resistance of the spring E and therefore a stronger currentmust be used to effect this result; The means for sending this currentover the wires will be described hereinafter. This current passes fromthe wires X X and X to wires E and through the magnets E. As the path,is the same in each case, we will describe it in one. The arms B are inthe position indicated in F 2. From the magnet E the current passes towire 15 ,410 Contact E", brush 1, wire (1 magnet C, wire C brush Ccontact C brush C, wire hell D, wire C, wire E any convenient points,not necessary to illus To effect this, it is necessary to move to theground, and thence back to central.

This eilergizes the magnet 'E, and its armature begins to move toward itand by the time it begins to overcome the resistance of. spring E"contact E on the armature will be engaged with brush E and a directcircuit from magnet E is established to the round,

as follows: from E to wire E wire L, contact E brush E wire E", and,wire F When this circuit-has beeniestablislied, the arm B will havebegun to move toward its normal position, and brush C will be disen- Wewill now refer to Figs. 4 and 5, which illustrate a preferred means fortransmitting movement from E to the arm B and to the arm and armature 0In Fig. 4 the parts as illustrated in full lines are in normal posi-*tion. If the armature (3 is operated, the end w of the arm 30 will moveup into close proximity, but not into contact with the end of theset-screw 36 in the armature E". There must be sufiicient space betweenthem to permit the movement of the armature E to release the fingerefrom finger b, as indicated in dotted lines, and when these fingers aredisengaged arm B will move into the po sition indicated by dotted lines,when itwill.

engage the stop 21, (shown in this case as a pivoted bar resting on astud 37.) A bolt 38 is connected at one end to the stop andextendsloosely through an opening in the armature fi'near'one end thereof. Thisbolt is provided with two adjustable' stops, (shown in' this case asnuts 39 and 40,) one above and the other below the armature E". Thesestops are so arranged that when the armature is in its normal positionneither will engage the armature. When the magnet E attracts itsarmature to release the fingers e and b, the armature will be free tomove until it is arrested bythe spring E without lifting the bolt 38,and this movement will be sufficient for this purpose. When, however,the magnet E operates to reset arm B and armature C", the are re E willmake a complete stroke and carry the bolt 38 up to the position shown inFig. 5, which will move the pivoted stop 21 to a position at rightangles to the arm B, and thereby force the latter back to its normalposi-' tion. When the armature E is released, the springs will force itback and bring its finger e in position to intercept finger b, and thenit will engage stop 40 and'force the bolt 38 downward, and therebydisengage the stop 21' from arm-B, and the stop 21 and bolt 38 will thencomplete" their returnto normal position by gravity. -The completemovement of the armature E under the influence of magnet E will alsocause the set-screw 36 to.

engage the end as of the arm 30, and thereby restore it and the armatureC to normal position.

Various means may be devised for sending the necessary currents over thewires X and X X by the operator at central, andin Fig. 6

' I have 'shown apparatus which may be used for this purpose. Thus forsending the strongest current over the wires X and X X for energizingthe magnets E to efiectthe resetting operation I provide a battery orother source of electrical supply S of the necessary capacity andprovide a switch-lever S, having contacts S and T insulated from eachother. Brushes S and S", adapted to be engaged by the contact S, arerespectively connected to'wires X X and X. One pole of the battery S iselectrically connected by a wire S to the contact S and the other "poleto the grornd. When the switch-lever S is moved to engage contact S withbrushes S and 8*, current from the battery will be sent over bothline-wires X X and X through magnets E to the ground, as alreadydescribed, and back to battery A portion of the same'battery S may beutilized for energizing magnets E for the purpose of releasing the armsB, which does not require so strong a current. Thus the contact T iselectrically connected by a wire T Witha portion only of the battery, asshown 'in Fig. 6. Two brushes T and T, adapted to be engaged by contactT, are respectively connected to wires X X and X, and when switch-leverS is moved to engage contact T with brushes T and T current from a por-*tion of battery S will flow over wires X X and X through magnetsA tothe ground and back to the battery S.

The current for energizing magnets C and bells D is preferably acontinuous vibratory current, and in Fig. 6 I have shown one means forsending a current of this character over the lines X and X X. Thus theline X is connected to a pivoted switch 0 by a wire 0, and the line X Xis connected to a similar switch 0 by a wire 0". A battery or othersuitable generator 0 is provided, and the positive polether'eof isconnected to a contact adapted to be engaged by either of the switches Oor O and its negative pole is connected to a contact 0, adapted to been. gaged by either of the switches 0-01 0 A commutator is provided ineach connection betweensaid contacts and the battery, and the latter isconnected to the earth. If the switch 0 be rocked to engage O, anegative current will be sent over line X, through magnets C, and-returnby the ground to battery 0 If switch Oengages O, a positive current willbe sent over line X and return through the grouml to'battery 0. Byopcrating switch O ithe same effects take placeover wire XX.

' Referring now to Fig. 7, wherein I have illustrated diagrammaticallyan apparatus at central and an apparatus at one substation on apaty-line in a central-energy system, it will be observed that themagnets E and C are empldyed insubstantiallythe same relations as-in thesystem heretofore described.

The generator F and its circuits are, however, omitted. celver G fromits support1ng-hook will serve In this case the removal of the re."

amaze to send a signal to central and automatically 1 ated, however, thecircuit will be closed at K send a current from central through themagnet (l to closeits receiver-oircuit.

Assuming the receiver G to be lifted from its hook l)", a circuit willbe established as follows: from book ll to wire 1), line-wire- X X,through battery M at central, contacts M and M wire M,- magnet M, wireiv to line-wire to wire U brush C contact C, brush i l, wire (1, magnet0, wire C brush (3 contact (1, brush C wire C contact 6"", to hoolr 17*.Current will then flow through magnet C from battery M and energize saidmagnet, thereby attracting its armature C and closing itsreceiver-circuit at G, G and (3. At the same time the mag net lil wilibe energized and attract its armature M", which will release the dropand at the same time engage contact M with brushes M and M and contact Mwith brushes N and M Current from the battery M will now flow over bothline-Wires X and X X to energize all the magnets E on the party-line, asbefore described, that for line X X flowing direct from the battery tothe liIlGrWIlIG X X and returning through the magnets E, connected tothat wire, the gr0und,,and contact- M. and brushes M and M to thebattery and that for line X flowing from the battery.

over wire M to brush M contact M brush M and wire M to wire X andreturning through the magnets E, connected to that wire, the ground, andcontact M and brushes M and M to the battery. Part'of the cur- .rentover M will also pass through magnet M back to the battery, and therebykeep the magnet energized and insure the operation of all the magnets E.

It will be observed that the magnets C are connected across theline-wires X and X X, and each will respond to the action of currentfrom battery M irrespective of its polarity, when its circuit is closedby its hook D engaging the contact C To effect this action, however, itwill be necessary to make slight changes in the comiections. betweenmagnet C and the brushes C and C Thus, assuming that magnet C-in Fig.7will respondto a negative current a magnet!) on the same line polarized.to respond to a positive current would have 1ts wire C connected tobrush =3 and1ts WlIB C connected to brush C, thus sending the currentthrough it in a reverse direction.

So far as sending out currents from central by an operator thereat for foperating magnets E and C for thepur oses already described inconnection with ig. 1 is concerned, the operations will be the same. Inthis case the circuit for the signal-bell,Kis

somewhat differently arrangedfrom that in Fig. 1 and is as follows: Allbell-circuits are normally open at K and C and at the hook D and contactC. When the arm B is operand C and then it a subscriber lifts hisreceiver from the hook at a substation other than one that may be usingthe line a circuit will be closed through the bell at such substation asfollows: from hook D to contact C Wire C wire C contact C brush K,

wire K through bell K to wire K brush K,

contact K brush K", wire K local battery K, to hook D At any substation,however, where magnet C has operated to close its receiver-circuit thelocal bell-circuit will be broken at K K and K, and the removal of thereceiver from the hook will not result in the ringing of hell K.

Without limiting myself to the precise details j of constructionillustrated and described, I claim- 1. In a telephone system" forparty-lines, the combination with the main-line wires leading from acentral station, of a series of telephone-receivers each independentlconnected to the line-wires by an open e ectric circuit, a polarizedmagnet and an armature at each substation for closing the circuit. ofits receiver, and a generator at each substation under the control tothe person thereat for sending an alternating currentthrough said magnetto energize it, substantially as set forth.

'2. In a telephone system for party-lines, the combination With themain-line wires leadingfrom a central station, of a series oftelephone-receivers each independently con nected to the line-wires byan open electric circuit, a polarized magnet and an armature itsreceiver, and means at each substation under the control of apersonthcreat for sending a current through said magnet to energize it,"to first close its own receiver-circuit, and then close a circuit at thecentral station for sending a current over the main.- line wires tooperate devices for preventing the closure of the receiver-circuit atany other substation on the line by a person thereat, substantially assetiorth.

3. In a telephone system fOrparty-lines, the combination with themain-line wires leading from a-central station, ofa series of telephonereceiVers each independently connected to the line wires by anopenelectric circuit, a receiver-circuit closer at each substation includinga polarized magnet and an armature, a signal at the central station, anda generator at each'substation under the 'control of a person thercatfor sending an alternating current through said magnet to energize itand cause it to close its own receiver circuit, and also close a circuitto the central" station to operate the signal thercat, sub stantially asset forth.

4. In a telephone system for party-lines, the combination with themain-line wires leading from a central station, of a series of thenon-polarized magnet for electrically con- 'telepl1onereceivers eachindepeinlently con nected to the line-wires by an open electric circuit,a receiver-circu t closer at each substation including a polarizedmagnet and an armature a signal at the central station, and a generatorat each substation under the control of a person thercat for sending analternating current through said magnet to energize it and cause it toclose its oWn receiver-circuit, and also close a circuit to the centralstation to operate the signal thereat, and also close a circuit at thecentral station for sending a current over the main-line Wires tooperate devices for preventing the closure of the receiver-circuit atany other substation on the line by a person thereat, substantially asset forth.

In a telephone system, the combination With the main line Wires leadingfrom a eentral station, of a telephone-receiver connected to saidline-Wires by an open electric car- ,cuit, a polarized magnet .md anarmature adjacent to said receiver, means For sending a current of thedesired polarity'through the magnet to operate its armature to close thereceiver-circuit, and means for preventing said magnet from breakingsaid receiver-circuit when a current of opposite polarity is sent,through it, substantially as set forth.

6. In a telephone system, the combination with the main-line WlIOSleading from a central station, of a telephone-receiver connected tosaid line-wires by anopen electric circuit, a polariz'edmagnet and anarmature adjacent said receiver, an arm pivotally supported adjacentsaid armature and carrying devices for closing said receiver-circuit andmeans for transmitting movement from the armature to said arm to closethe receiver-circuit when the magnet is energized by a current of onepolarity but inoperative to move said arm when the magnet is energizedby a current of opposite polarity, substantially as set forth.

7. The combination with main line Wires, of a telephone-receiverconnected thereto by an open electric circuit, a polarized magnet and apivoted armature, an arm carrying devices for closing thereccivercircilit, said arm having an opening into which the arm-atureloosely tits and being pivotally supported on the pivots ol' thearmature, and a bar secured to the arm and extending across said openingto be engaged by one end of the mature, substantially as set forth.

8. In a telephone system for party-lines,

the combination ot main-line wires leading from acentral station, ofas'eries ot' telephonereceivers each connected to the line\\'ires by anopen electric circuit, a polarized magnet and arm atnrc at eachsubstation for closing its (),\\'H receiver-eircuit, a polarized bell ateach substation, a non-polarrzed magnet at each substation, and meansoperated by necting the polarized magnet, the polarized bell and itselfin series to receive a polarized current over the mam-line wires fromthe central station, substantially as set forth. 7o

9. In a telephone system for party-lines, the combination of 1nain-lineWires leading from a central station, of a series of telephone-receiverseach independently connected to the line-Wires by an open electriccentral station, over the line-wires to energize the non-polarizedmagnets, means operated by the non-polarized magnets to prevent theclosure of their respective receiver-circuits by persons at therespective substations, and

means for sending a polarized current from the central station foroperating the polarized magnets selectively to close their respectivereceiver-circuits, substantially as set forth.

'10. In a telephone system for party-lines,

the combination of main-line Wires leading 0 from a central station, ofa series of telephonereceivers each independently connected to themain-line Wires by an open electric circuit, a,polarized magnet andarmature at each substation for closing-its own receiver 5 circuit, apolarized bell at each substation, a non-polarized magnet and armatureat each substation connected to one of the line-Wires, the said magnetsand bell being normally deenergized, and circuit-closing devices con-10o trolled by said non-polarized magnet for electrically connecting thebell and magnets at each station in series, substantially as set forth.

11. In a telephone system for party-lines, to

the combination of main-line wires leading from a central station, of aseries of telephonereceivers each independently connected to" themain-line Wires by an open electric circuit, a polarized magnet andarmature at each substation for closing its own receivercircuit, apolarized bell at each substation, a nonpolarized magnet and armature ateach substation connected to one of the line-Wires, the said magnets andbell deenergized, a'pivoted arm carrying circuitclosing devices normallybiased to move in onedirection and restrained from such movement by thearmature of the non-polarized magnet, and means for sending a currentthrough said non-polarized magnets for releasing said arm to closecircuits for connecting the bell and nn'ignets at each station in.series, substantially set forth.

12. In a telephone system for party-lines,

the combination of main-line wires leading from a central station, of aseries of telephone receivers each independently connected to themain-line Wires by an open electric cir cuit, a polarized magnet andarmature at being normally 115 each substation for closing its ownreceivercircuit,ia polarized bell at each substation, a non-polarizedmagnet and armature at each substation connected to one of theline-Wires, the said magnetsand bell being normally deenergized, apivoted arm carrying circuitclosing devices normally biased to move inone direction and restrained from such movement by the armature of. thenon-polarized magnet, means for sending a current through i saidnon-polarized magnets for releasing said arm to close circuits forconnecting the bell and magnets at each station in series, and meansoperated by the non-polarized magnet for restoring the arm to normalposition, substantially as set forth.

13. The combination with the main-line wires, of a telephone receiverconnected thereto by an open electric circuit, a magnet C and armaturefor closing said circuit, a bell, a second magnet E connected to one ofthe line-Wires, an armature for said magnet, said magnets and bell beingnormally out of circuit with each other, a pivoted arm carryingcircuit-closing devices, said arm being normally biased to move in onedirection and restrained from such movement by the armature of themagnet E, means for sending a current through the magnet E to attractits armature and release said arm to close circuits for connecting thesaid magnets and bell in series, substantially as set forth.

' 14. The combination with the main-line Wires, of a telephone receiverconnected thereto by an open electric circuit, a magnet C and armaturefor closing said circuit, a bell,

a second magnet E connectedto one of the line-Wires, an armature forsaid second magnet, said magnets and bell being normally out of circuitwith each other, a pivoted'arm carrying circuit-closing devices, saidarm being normally biased to'move in one direction and restrained. fromsuchmovement by the armature of the magnet E, means for sending acurrent throng 1 the magnet E to attract its armature and release saidarm to close circuits for connecting the said magnets and bell inseries, a pivoted bar forming a stop to limit the movement of the saidarm, and connections between said bar and the armature of the magnet Efor restoring said arm to its normal set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

' KOBY KOHN.

position, substantially as Witnesses C. A. Ar uNsoN, F. L. B. JENNEY

